This application is related in general to power supplies, and in specific to a N+1 power supply system that can be configured for different input AC power formats.
Large, multi-processor computer systems are business enterprise servers for use by large corporations with high speed computer needs, e.g. automotive companies, large accounting firms, Internet companies, etc. Enterprise servers take large amounts of AC current from the site power, typically on the order of 10-20 kilowatts of power. Therefore, 3-phase power is usually used to power these systems. One of the major requirement for enterprise servers is what is called high availability. The meaning here is that there is the desire that there are no external events force the machine to crash. One common event that leads to a system crash is loss of the system power. This may occur as a result of a commercial power producer problem or it may originate with loss of a system power component. Note that with three phase power, the problem can be from the loss of the entire 3-phase grid, or loss of one of the three legs.
To avert such failures, enterprise server customers generally try to have an un-interruptible power supply or back-up motor generator running their systems. In this case, the un-interruptible power supply, or UPS, is always online and of course, it too can fail. What was needed, then, was a different way to ensure availability and reliability.
One typical way is to have two power grids available for the product. One power grid could be the site 3-phase power, and the other one could be an un-interruptible power supply or perhaps even a motor generator. Thus, when a failure is sensed on one of those power grids, an active switch mechanism changes the power feed to the computer product. In other words, if grid A failed, it would be sensed and grid B would be switched over into the machine. There are problems with this approach, primarily because the phase relationship between grid A and grid B must be the same. Also, the tolerances of the power should also be the same, i.e. the power supplied by both grids should have the same voltages and current levels. The biggest problem is that there is a latency time relating to that switchover. Thus, the computer may suffer a power drop during switch over, and thus may crash. Systems with such backups are referred to as N+1 systems, the N being the required number of power grids, the +1 being the backup grid.
These and other objects, features and technical advantages are achieved by a system and method which uses modular N+1 power sources. Thus, the individual power supplies, or bulk power supplies (BPSs) may be swapped out of the computer. The BPSs supply power to the computer components. The power supply system uses a plurality of BPSs according to an N+1 requirement. For example, if 5 BPSs are required to run the computer system, then 6 BPSs would be installed in the power supply system. Thus, if one BPS goes down, the remaining five can satisfy the system""s power needs. This also allows the BPSs to be hot swappable, meaning that a BPS can be changed for a new one, without shutting the system down. This allows for the system to be repaired, e.g. defective BPSs can be swapped, or upgraded, e.g. a newer model replaces an older one. This also allows for repairs or modifications to be performed while the system is running, e.g. one BPS is pulled for repair/modification, while the other BPSs provide power to the system.
Each BPS is split into two halves, with each halve being run by a separate power grid. This means that if one of the power grids goes down, the other grid fills the power. Thus, there are no switching times or latencies, the inventive power supply system keeps running. When both power grids are present, each power supply halve in a BPS load shares 50/50. To make this possible, it was necessary to be able to accommodate two input power grids of basically any voltage between 176 and 284 VAC. The phase relationship of these voltages is unimportant.
The two input AC power grids are each controlled separately via two power distribution control assemblies (PDCA). Each assembly can be separately configured for 3 phase wye or 3-phase delta inputs. Each PDCA can also be separately configured to receive single phase power. Each PDCA divides the power among the BPSs. The wiring blocks used to configure the PDCA for any 3 phase wye, 3-phase delta inputs, or single phase are field configurable, and can be changed out to permit a different power input. Thus, if one power grid or PDCA goes down, the BPSs will pull their power needs from the other PDCA and grid. Thus, if one PDCA goes down, the remaining one can satisfy the system""s power needs. This also allows the PDCAs to be hot swapped, meaning that a PDCA can be changed for a new one, without shutting the system down. This allows for the system to be repaired, e.g. defective PDCAs can be swapped, or upgraded, e.g. a newer model replaces an older one. This also allows for repairs or modifications to be performed while the system is running, e.g. one PDCA is pulled for repair/modification, while the other PDCA provides power to the system.
Therefore, it is a technical advantage of the present invention to be able use any form of power to supply the computer system, e.g. 3-phase delta power, 3-phase wye power, single phase power, motor generated power, or UPS power. Any of these configurations can be accommodated as either the primary and/or the backup power source.
It is another a technical advantage of the present invention to be able have a two way redundant power supply. One is AC input power redundancy, via two PDCAs. The other is DC power redundancy, via N+1 BPSS.
The foregoing has outlined rather broadly the features and technical advantages of the present invention in order that the detailed description of the invention that follows may be better understood. Additional features and advantages of the invention will be described hereinafter which form the subject of the claims of the invention. It should be appreciated by those skilled in the art that the conception and specific embodiment disclosed may be readily utilized as a basis for modifying or designing other structures for carrying out the same purposes of the present invention. It should also be realized by those skilled in the art that such equivalent constructions do not depart from the spirit and scope of the invention as set forth in the appended claims.